Hi,
I'm a complete n00b when it comes to arduino's! I've never touched one. I'd be using a small kit chassis (4wd) with a GPS Module and an Arduino Uno.
As far as programming goes, i know HTML, Basic PHP and Visual Basic.
Essentially, i'd like this robot to navigate itself to set waypoints, how hard would this be?
In HTML? Impossible!
I Know that much ;D
Seriously though, having never touched C/C++, how hard would it be to tackle a project like this?
Just so you know, you can't program in HTML, since nothing gets executed.. ever 
HTML is a mark-up language, not a programming or scripting one.
As for the difficulty of making such a robot... it depends on the complexity you're after I geuss.
The only way to find out is to dive in, get each seperate component working first (ie: simply making the arduino drive the bot, make the arduino retrieve GPS data, that sort of stuff) and when you have it all working on a basic level, and you understand what it does, make a new sketch that incorporates several/all of the functions it has to do.
Just so you know, you can't program in HTML, since nothing gets executed.. ever HTML is a mark-up language, not a programming or scripting one.
You sure? A browser executes the html and does a bunch of stuff depending on what is contained in the html. You can use html to make a GUI to control a robot if desired similar to below.
hey neodude112320,
I didn't know any C/C++ when I started using Arduino and it wasn't too hard to get started. Luckily, there are lots of resources on the web. My first project was a Braitenburg vehicle and it took me about 1 day to put it together (and most of the day was spent shopping for the right parts).
You can see my light seeking robot here: http://www.alivingarchitecture.com/2010/11/braitenberg-vehicle/
Depending on how much more complex your project is, you can figure out how long it would take you... good luck!
You sure? A browser executes the html and does a bunch of stuff depending on what is contained in the html. You can use html to make a GUI to control a robot if desired similar to below.
Quite sure.
Quite sure.
Really? From your link it sure looks like the html controls the browser to make your computer display and do different things.
"The purpose of a web browser is to read HTML documents and compose them into visual or audible web pages. The browser does not display the HTML tags, but uses the tags to interpret the content of the page."
A manned robot might be an easier option 
hehe
But there are a lot similar existing projects.
Google "DIY Drones" although they are mainly planes, my guess is you can find a lot of info, code, hardware lists etc.